Iranian President Mahmoud Ahmadinejad said on Thursday that the United States must make its position on Israel's nuclear strategy clear before talks on Tehran's atomic program could resume.

Sanctions imposed by "arrogant" Western powers would not slow Iran's nuclear progress, he said.

The United States, Europe and the United Nations have imposed sanctions on Iran over its nuclear program. Iran says its aim is to generate electricity and rejects Western suspicions it is seeking to build a nuclear bomb.

Iran's chief nuclear negotiator suggested in a letter to the European Union's foreign affairs chief this week that talks could be held as soon as September on issues including Tehran's atomic program.

Speaking in Nigeria after a summit of the D8 group of developing nations, Ahmadinejad said Iran supported dialogue but blamed the United States for the failure of previous talks.

Asked what conditions must be met for talks to resume, Ahmadinejad said Washington must make its position on Israel's nuclear strategy clear.

"The first condition is they should express their views about the nuclear weapons of the Zionist regime. Do they agree with that or not. If they agree that these bombs should be available to them, the course of the dialogue would be different," he said.

Israel is widely assumed to have the only nuclear arsenal in the region but it refuses to confirm or deny having such weapons.

The Zionist entity has usually been spared scrutiny by its guardian ally but the Obama administration alarmed Israel in May by backing an Egyptian initiative for talks in 2012 on a Middle East free of weapons of mass-destruction.

However, hosting Israeli Prime Minister Benjamin Netanyahu on Tuesday, US President Barack Obama echoed Israel's veiled justifications for having the bomb and said Israel had "unique security requirements".

The White House said Obama had further pledged to keep Israel, which has not signed the Non-Proliferation Treaty, from being "singled out" at a meeting of the UN nuclear watchdog in Vienna in September as well as at the Egyptian-proposed regional conference.

Ahmadinejad, speaking to reporters through an interpreter, said the United States must also clarify its own commitment to non-proliferation and its position on its readiness to "resort to force".

Ahmadinejad has been outspoken in his dismissal of the new sanctions, adopted by the UN Security Council and several Western governments, previously calling them a "used hanky which should be thrown in the dustbin".

But the head of Iran's atomic energy, Ali Akbar Salehi, acknowledged for the first time on Wednesday that the measures "may slow down" its nuclear drive. "One can't say sanctions are ineffective," Iran's ISNA news agency quoted Salehi as saying.